Notes on the taxonomy of the Philippine endemic Porphyra marcosii Cordero (Bangiaceae, Rhodophyta)

Abstract

Porphyra marcosii Cordero is an economically important species considered to be endemic to the northern Philippines. This foliose, monostromatic species with microscopic teeth was first described based on a sample from Dirique Bay, Burgos, Ilocos Norte, in north-western Luzon (Cordero 1976, 15: figs A-H, pl. 1). Together with other foliose Bangiales, Porphyra marcosii is locally known as “gamet” and collected from the wild, dried as sheets called “pedazo”, and sold in local markets for consumption as food (Trono & Ganzon-Fortes 1988, Prud’homme van Reine 2001, Cordero 2008). Ogawa (2001) noted the overlap in the morphological characters of Porphyra marcosii with the earlier described Porphyra vietnamensis Tak.Tanaka & P.H.Hô (Tanaka & Hô 1962), now known as Phycocalidia vietnamensis (Tak.Tanaka & P.H.Hô) Santiañez & M.J.Wynne (Santiañez & Wynne 2020). Ogawa (2001) alluded that the two species are conspecific. Prud’homme van Reine (2001) also considered Porphyra marcosii as heterotypic synonym of Porphyra vietnamensis. However, Porphyra marcosii is still regarded as distinct by some authors (e.g., Cordero 2008, Monotilla & Notoya 2010, Dumilag & al. 2017, Dumilag & Monotilla 2018).